Closed multi-fluid delivery system and method

ABSTRACT

A multiple fluid delivery system usable for the delivery of intravenous fluids to a patient from a plurality of fluid sources includes flexible tubing members for coupling the sources to a fluid junction member. The fluid junction member, wherein little or no interfluid mixing occurs, is coupled by an output conduit to a controllable pump. Output from the pump, via a further fluid flow conduit, can be coupled to the patient&#39;s catheter. The system can multiplex a plurality of different fluids. Spaced apart sequences of fluid quanta are injected into the output conduit from the fluid flow junction. The fluids are either mixed, or not, in the output conduit as desired. Operator interaction and control of the system can occur either through a display screen or by means of a bar code sensor. Hard copy records can be provided of fluid flow delivery schedules or other related information.

FIELD OF THE INVENTION

The invention pertains to the field of drug delivery systems andmethods. More particularly, the invention pertains to apparatus andmethods for controllably providing a plurality of different fluids to asingle fluid-flow conduit for delivery in predetermined proportions atpredetermined rates.

BACKGROUND OF THE INVENTION

The intravenous infusion of various types of medicated fluids intopatients has become an important part of the treatment of many differentdiseases. In addition, such multiple fluid infusion programs have alsobecome an important part of the treatment of patients with trauma orpatients injured in accidents. Such patients often receive their acutetreatment in intensive-care units. In many institutions,immuno-suppressed patients such as bone marrow and other transplantpatients also receive multiple intravenous fluids over a substantialperiod of time.

Depending on the physician's orders, these fluids are delivered to thepatient by means of a surgically inserted, main-line catheter or at aperipheral site, such as the patient's arm or leg. Because of thecondition of many of these patients, it is especially critical that thecorrect drug doses be administered at the correct rates during thedesignated periods of time. Further, many such patients become highlyvulnerable to infections or may have depressed or damaged immunesystems. Therefore, it is important to minimize, to the greatest extentpossible, the potential entrance of infectious agents into the flow offluids being administered.

Multiple fluid intravenous infusion has been practiced in the prior artby hanging containers of solution from an IV administration pole. Thepole might be mounted on wheels to make it transportable. An initialsolution is hung, and using aseptic technique is coupled to thepatient's catheter. The nurse or other health professional adjusts therate of flow by timing the rate of fluid drops falling in a drip chamberwhile manually adjusting a clamp valve.

To add a second fluid without adding another injection site to thepatient, a fluid-flow junction, sometimes referred to as a "Y" site, ora "Y" junction is provided. This junction is located in the initialfluid-flow delivery tube. The second container of solution is coupledinto an unused input of the "Y" junction. The rate of flow of the twosolutions can be readjusted by means of manually operable clamps anddrip chambers associated with each of the solution containers and byadjusting the relative heights of the containers.

If a third solution is required, a second "Y" junction it providedlocated in the administration line associated with the second fluidcontainer is utilized. The third fluid-flow container is coupled intothe second "Y" junction and the rates of flow are again, manuallyadjusted as before.

There have been a number of recognized problems associated with theabove-described fluid-delivery systems. One immediate problem is thefact that use of gravity-flow and drop counting does not necessarilyensure that the desired flow rates to the patient will be maintained orwill be sufficiently accurate. This is aggravated if the patient is tobe moved such as for x-rays, cat scans or therapy. Such movement isdifficult and cumbersome, while fluid is still being administered.

To overcome these problems it has become standard practice to useelectrically powered infusion pumps which can be set to deliver apredetermined quantity of fluid through a fluid-flow conduit at apre-determined rate. Such pumps lend themselves to portable usage.Usually they are mounted right on the fluid delivery pole, which isitself mounted on casters. Such pumps are often provided with batteryback-up to provide portability and to provide several hours ofuninterrupted service in case of main power failure.

Known prior art systems do not provide for appropriate automatic controlof the various substances being delivered. In addition, multiple linesmay need to be run between the patient and the plurality of infusionpumps to provide the necessary multiple drug therapy.

A step in the direction of attempting to deal with this problem isillustrated in U.S. Pat. No. 4,512,764 issued to Wunsch. The Wunschpatent provides for a plurality of fluid-flow solution containers whichcan be interconnected by a fluid-flow transfer set and a set of manuallyoperative valves. Output from the manually operable valve system iscoupled to a single fluid-flow conduit. This conduit passes through aperistaltic pump and then on to the patient. The manually operablevalves are opened and closed at various periods of time to deliver thedesired fluids.

In another patent, U.S. Pat. No. 4,559,036 also to Wunsch, a computercontrolled set of valves is illustrated. The system of this latterWunsch patent includes either motor activated or solenoid controlledvalves which are connected to the control unit. Further, this systemprovides for a timing cycle, during which various valves areindependently and successively opened for predetermined time intervalsto permit the flow of various fluids to a patient.

Other multiple-fluid infusion systems have also been proposed whichinclude various types of electronic control units. One aspect of anysuch system is the fluid-flow delivery set which is utilized in theapparatus. Some of the known delivery sets are relatively complex andexpensive.

Extensive experience has taught that sterile, limited use, disposable,fluid-flow transfer sets can be cost-effective. Such sets can also bevery effective in minimizing the possibility that infectious agentsmight inadvertently be delivered to the patient. However, such sterilelimited-use, transfer sets do not in themselves solve the problem ofcontrolling the infusion of a variety of different fluids to produce adesired composite fluid flow.

One known alternate is to use a multiplicity of infusion pumps, eachcoupled to one or more sets of solution containers. In this embodiment,two or more lines, each associated with a respective infusion pump, arebrought to the patient and are coupled in an aseptic fashion to thepatient. Such systems tend to be very flexible and are assembled at thepatient's bed side. Nevertheless, they result in a cluttered, confusingsystem and represent substantial control problems from the point of viewof the delivered fluid flow.

From a practical perspective, there is always a problem in anyarrangement having multiple IV infusion poles, multiple pumps, multipleelectrical cords and multiple sets of lines running from the containersto the pumps and from the pumps to the patient. When an attempt is madeto move the patient, all of the poles must be moved in unison. This isnot too difficult with one pole. It can be manageable with two poles. Itbecomes very difficult with three poles.

There is thus a continuing need for a closed, relatively portableuncluttered system which will provide for multiple, essentiallysimultaneous delivery of a plurality of different sterile fluids understerile conditions. Preferably such a system would provide the abilityto reduce potential contamination problems by reducing the number andcomplexity of tubes and junction members necessary to effectuatedelivery of the fluids.

Such a system preferably would provide the ability to prepare plannedmedications and fluid-flow delivery sequences which would extend oversubstantial periods of time, such as 24 hours. Further, such systemswould preferably utilize main-line catheters for the purpose of reducingthe number of or eliminating various vein punctures usually necessaryfor the delivery process.

In addition, such a system should provide for the relatively long-termscheduling of delivered medications, such as over a 24 hour period.Further, such a system should provide assistance to the nursing staff ofan institution in a variety of ways. The multiplicity of differentinfusion pumps should be reduced to the greatest extent possible.

The system should also be relatively user friendly and easy for theprovider of care to work with. Further, such a system should assist inrecordkeeping such as by generating hard-copy while at the same timebeing relatively silent in operation to avoid disturbing the patient andunobtrusive in function.

SUMMARY OF THE INVENTION

In accordance with the invention, a closed, multiple-fluid deliverysystem is provided. The system can deliver a plurality of preselectedfluids in a preselected sequence via a closed fluid-flow delivery systemto an output port.

The system includes a plurality of deformable fluid-flow tubing orconduit members. The tubing members can have a spike connector at oneend for insertion into an access port of an intravenous fluid container.Each other end of the tubing members carries a selected connector suchas a luer twist-lock connector or a hollow piercing needle. The systemincludes a fluid-flow junction member into which the second end of eachof the conduits is coupled.

A plurality of electrically controlled occluders, one associated witheach conduit member, provides for controllably turning the fluid flowfrom a respective container on and off. The fluid enters into thejunction member and flows into an output conduit. Pumping means areprovided to effect the fluid flow and deliver the combined fluid flow ata controllable rate.

The electrically actuated occluders, as well as the pumping meansfunction in conjunction with a programmable control unit. Theprogrammable control unit includes means for storing and executing oneor more fluid delivery schedules which can extend over a substantialperiod of time, such as 24 hours and for controlling the on/offsequencing of the occluders as required by the programmed schedules.

Further, the control unit includes information relating to inter-fluidand drug compatability important in intravenous drug delivery. Thecompatability between various specified fluids and the drugs compoundedinto them can be examined prior to activating the scheduled deliverysequences. The control unit also provides control circuitry to actuatepumps to provide the required combination of flow rate and volumedelivered at the specified times at the output port.

Each occluder controls the on/off flow of fluid from its assigned fluidcontainer. In operation the system intermittently actuates selectedoccluders for selected periods of time, so as to provide at the outputof the junction a plurality of sequentially delivered fluid quanta froma sequence of fluid containers. This is termed fluid multiplexing. Thesequanta then intermix while flowing through an output fluid-flow conduitto the fluid port, effectively providing essentially simultaneousdelivery of multiple fluids.

By appropriately prolonging the open and close time intervals ofselected occluders, the system is capable of delivering the fluids in ascheduled, nonmultiplexing, intermittent or continuous mode.

Further, in accordance with the invention, the control unit regulatesthe actuation or timing of the electrically controlled occluders suchthat as the fluid administration is subjected to scheduled changes overthe course of a predetermined time, the scheduled output flow rate ismaintained with respect to the various fluids being provided and anyfluid-flow transients due to the schedule changes can be minimized.Transients are minimized by inserting compensation phases into thepredetermined delivery schedule.

The electrically energized occluders can be implemented as solenoidactuated clamps. Each clamp has a biasing mechanical return/fluid shutoff spring.

The clamp, in response to a first level of applied electrical energy,can move from a first fluid-flow blocking position to a second, fluidflow enabling position. The clamp can be held in the second position ata lower level of electrical energy than was required to get therepermitting a flow of fluid through the respective fluid delivery conduitwith a low expenditure of electrical energy. The biasing member isavailable to immediately return the clamp to its first, fluid-flowblocking position, in response to the removal of the second level ofelectrical energy.

Resilient means are provided to resiliently slow and stop the movementof the clamp in response to the applied first level of electricalenergy. This provides for quiet operation of the clamp as it moves froma closed position to an open position. On closure, the tubing membercushions the moving portion of the clamp.

In accordance with the present invention, a fluid junction is provided.This fluid junction region includes a plurality of fluid input ports.The fluid input ports can be sealed with a luer type connector or apierceable septum. The pierceable septum has a thickness on the order0.25 7 mm to provide for supporting at least two inserted fluid deliveryneedles simultaneously as well as for reclosing upon removal of aninserted fluid delivery needle.

The fluid junction of the present invention provides a completely sealedfluid flow delivery system. In combination with known aseptictechniques, this system can provide a single combined flow of sterileintravenous fluids from a variety of fluid-flow sources to the patient.

The fluid junction can also include an output port to which is coupledthe fluid-flow output conduit. A free-end of the fluid flow outputconduit in turn can be coupled to the patient.

An additional port can be provided to make possible the coupling of twoor more of the fluid junction members together to increase the number offluid sources that can be used as input sources to the output fluid-flowconduit.

Further, in accordance with the invention a fluid-flow delivery systemis provided. The fluid-flow delivery system includes a plurality offlexible fluid-flow delivery conduits, each with a connector at a firstend suitable for coupling to a fluid-flow source, such as flexiblecontainer of sterile intravenous fluid either compounded or not withdrugs. At a second end, each of the conduits carries a second couplingmember for coupling into a fluid junction member.

When coupled together, the sources of fluid, the conduits and the fluidjunction member provide a completely closed system in which varioussources may be utilized to provide known quantities of selected fluids.These fluids are permitted to pass through the junction member into anoutput port of the junction member.

Coupled to the output port of the junction member is an outputfluid-flow conduit. The output conduit can be of a type which at a freeend has a connector couplable to a catheter of a patient. The entirefluid flow delivery system can be formed as a sterile disposable,single-patient delivery system. After a predetermined period of time thesystem would be replaced with another similar, sterile disposabledelivery system.

The output fluid flow conduit can be formed with a smaller diameterregion, on the order of 0.065", than other tubing members which can havea diameter on the order of a 0.100 inches. This reduced diameter regionprovides for more precise control of the volumes of delivered fluids.

Further, in accordance with the invention, a method is provided whichcombines a plurality of fluids from different sources into a continuous,predetermined, composite fluid flow at an output port. The methodincludes the steps of providing a sequence of known quantities ofdifferent fluids, in a predetermined order, at a first end of afluid-flow output member. The method further provides for mixing thevarious discrete quantities of different fluids in the output member soas to provide at a second end of that member, a continuous fluid-flowhaving predetermined proportions and at a predetermined rate such that apredetermined volume of each selected fluid is provided at the outputport during a selected time interval.

Further, in accordance with the present invention, the method providesfor checking the compatability of a selected predetermined set of fluidsto be provided and any drugs which may be compounded into them todetermine that such fluids can be delivered simultaneously withoutundesired interaction with one another. In accordance with the method ofthe present invention, the combined fluid-flow output can be deliveredto the output port at a controlled rate by a pump. Alternately, thecombined fluid-flow output can be delivered by means of the force ofgravity.

Numerous other advantages and features of the present invention willbecome readily apparent from the following detailed description of theinvention and the embodiments thereof, from the claims and from theaccompanying drawings in which the details of the invention are fullyand completely disclosed as part of this specification.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic view of a prior art, manually stacked multi-fluiddelivery system;

FIG. 1B is a set of graphs of fluid flow vs. time for the deliverysystem of FIG. 1A;

FIG. 2 is a perspective view of a multi-fluid delivery system inaccordance with the present invention;

FIG. 3 is an over-all block diagram of the fluid flow system of FIG. 2;

FIG. 4 is a schematic diagram of a disposable set usable with the systemof FIG. 2;

FIGS. 5A-5E illustrate alternate forms of the fluid junction member ofthe system of FIG. 2;

FIG. 5F is a fragmentary, enlarged sectional view taken along plane5F--5F of FIG. 5B;

FIG. 6 is an electronic block diagram of the system of FIG. 2;

FIG. 7 is a detailed block diagram of an occluder electronic interfacein the system of FIG. 2;

FIG. 8 is an electro-mechanical diagram of an electrically operatedoccluder partly in section;

FIG. 9A is a schematic diagram of an electronic drive circuit for usewith the occluder of FIG. 8;

FIG. 9B is a graph of voltage applied to an occluder by the drivecircuit of FIG. 9A;

FIGS. 10A-10C taken together are a flow diagram illustrating thespecification of a plurality of drugs or solutions to be infused by thesystem of FIG. 2;

FIG. 11A is a schematic diagram of the System of FIG. 2 used to providea three component fluid flow to a patient;

FIG. 11B is a set of graphs of fluid flow vs. time for the system ofFIG. 2;

FIG. 11C is a graph of fluid flow quanta vs time illustrating fluidmultiplexing in accordance with the present invention;

FIG. 12 is a view in section of a portion of an output tubing memberillustrating spatially spaced-apart quanta of several fluids beingdelivered by the system of FIG. 2;

FIGS. 13A and B together form a flow diagram of the method ofmultiplexing in accordance with the present invention;

FIG. 14A illustrates a prior art apparatus for introducing a secondfluid into a flow of a first fluid;

FIG. 14B is a pair of graphs illustrating the change in concentration influids A and B in the tubing member 388 of FIG. 14A as fluid B flowsthrough;

FIG. 15A illustrates a system for mixing fluids which employs computercontrolled occluders;

FIG. 15B is a pair of graphs illustrating the change in concentration offluids A and B in the tubing member 90 of FIG. 15A;

FIG. 16 illustrates the calculated mixing volumes for the systems ofFIGS. 14A and 15A during the time intervals when fluids A and B aremixed in tubing members 388 and 90 respectively; and

FIG. 17 illustrates an alternate occluder head usable with the computercontrolled occluders in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawing and will be described herein indetail a specific embodiment thereof with the understanding that thepresent disclosure is to be considered as an exemplification of theprinciples of the invention and is not intended to limit the inventionto the specific embodiment illustrated.

To assist in the description of the present invention, a prior artthree-bag infusion System 10 is illustrated in FIG. 1A. The desiredschedule of fluids to be delivered to a patient P is 20 ml/hr of fluid1, 20 ml/hr of fluid 2 and 50 ml of fluid 3 to be delivered at 100ml/hr.

The System 10 includes three containers, 12, 14 and 16, each of whichcontains a predetermined quantity of fluids 1, 2 and 3 respectively. Thecontainers are coupled by flexible fluid-flow conduits, 20, 22 and 24along with two "Y" connectors, 26 and 28 and an intermediate tubingsection 30 to an output fluid-flow conduit 32. Conduit 32 is coupled bya catheter C to the patient P.

Each of the lines 20, 22 and 24 includes an infusion pump 21, 23 and 25respectively. Each of the pumps 21, 23 and 25 may be adjustedindependently.

By way of a typical example, containers 12 and 14 which are sources forfluids 1 and 2 are adjusted and operating so as to supply 20 ml per hourof fluid in each of lines 20, 22 with the result that in line 32, 40 mlper hour of fluid is being provided to the patient. The fluid flow inthe line 32 being delivered to the patient P contains equal quantitiesof each fluid as illustrated in the bottom graph of FIG. 1B at all timesless than 30 minutes.

The volume of the line 30 is about 1.5 ml. The volume of the line 32 isabout 3.0 ml including the catheter to the patient.

At the 30 minute point, without changing the flow rates of eithertubular member 20 or 22, tubular member 24 is opened and adjusted to adesired steady state flow rate of 100 ml per hour for a period of 30minutes. The upper graph of FIG. 1B illustrates the flow of fluid 3 inthe tubular member 24. However, an investigation of the fluid flow inthe tubular member 30 which represents the composite of fluids 2 and 3,as illustrated in the middle graph of FIG. 1B, demonstrates a veryunexpected and undesirable change.

Immediately upon initiation of the flow of fluid 3, the rate of flow offluid 2 in the tubing member 30, which is full of fluid 2, jumps to 120ml per hour. This rate is six times the desired flow rate of fluid 2.This substantially greater flow rate of fluid 2 continues in the line 30for approximately 0.75 minute. At that time, the spike of fluid 2 dropsand the flow rate of fluid 2 returns to its prior predetermined value of20 ml per hour. However, it should be noted that depending on thecontents of container 14, the fact that fluid 2 has jumped from adesired flow-rate of 20 ml per hour to a flow rate of 120 ml per hour inthe line 30 might lead to very undesirable results in the patient'stherapy.

Subsequently, at the 60 minute interval, corresponding to the periodwhen fluid 3 is nominally to be completed, container 16 has been emptiedof fluid 3. The flow rate of fluid 3 in the line 30 then drops, but notto zero. Instead, as illustrated in the middle graph of FIG. 1B, theflow rate of fluid 3 drops to about 17 ml per hour for about 4.5minutes. At the end of this period, all of fluid 3 in the line 30 hasbeen drained into line 32. Line 30 is again filed with fluid 2.

The bottom graph of FIG. 1B, illustrates the transient fluid flow of theoutput line 32 to the patient P. At the 30 minute point, when the flowof fluid 3 in the line 24 is initiated, a spike appears in the flow rateof fluid 2 being delivered to the patient P. The flow rate of fluid 2jumps from the prescribed rate of 20 ml per hour to the patient toapproximately 70 ml per hour for about 1.3 minute. It then jumps to 120ml per hour for about 0.64 minute.

These two jumps represent respectively over 3 times and about 6 timesthe prescribed flow rate for fluid 2 being delivered to the patient. Inthe same two time intervals, fluid 1 jumps from a prescribed flow rateof 20 ml per hour to a flow rate of approximately 70 ml per hour andthen drops to a flow rate of approximately 20 ml per hour.

Hence, in the first two minutes that the fluid 3 is being ostensiblyadministered to the patient, none of fluid 3 has reached the patient P.Instead, a combination of fluids 1 and 2 in the lines 30 and 32 isreaching the patient at flow rates substantially greater than prescribedfor those two fluids. For the remainder of the time, until the 60-minutepoint, fluids 1, 2 and 3 are delivered to the patient at the prescribedand expected rates of 20 ml per hour, 20 ml per hour and 100 ml per hourrespectively.

At the 60-minute point the pump 25 has stopped pumping fluid 3 from thecontainer 16. However, a quantity of fluid 3 is still in the process ofdraining through the tubing members 24, 30 and 32. Immediately after thepump 25 has stopped, the overall flow rate in the line 32 drops to 40 mlper hour.

However, the 40 ml per hour for about a 9 minute time period illustratedin the lower graph of FIG. 1B at region 34 is composed primarily ofcontinuing flow of fluid 3 from lines 30 and 32 with very little flow offluids 1 and 2. The continuing flow rate of fluid 3 in this timeinterval is on the order of 28.6 ml per hour. After about 4.5 minutes,the flow rate of fluid 3 drops to about 16.7 ml per hour and continuesat 16.7 ml per hour for another 4.5 minutes. It's only after thisadditional period of time that the fluids 1 and 2 return to theprescribed steady state value.

Hence, the system 10 described above has failed in several significantways to deliver the desired fluids at the prescribed flow rates. It isbelieved that the heretofore unsensed and uncompensated for variationsin flow rates due to fluid flow transients may be the source of variousartifacts and unexplained test results experienced from time to time inthe past. For example, if a test were to be conducted, during the timeperiod indicated by the arrow 34, of the effects of fluid 3 on thepatient on the assumption that fluid 3 has already been fully beenprovided to the patient P, the test results could be erroneous. Thiserroneous reading could be due to the fact that fluid 3 is still flowingto the patient during this time interval. In fact, fluid 3 continuesflowing to the patient for about 7 to 8 minutes longer than nominallyexpected.

The fact that 1 and 2, for a 3/4 minute time interval were delivered atsubstantially greater rates than prescribed could also lead to erroneoustest results.

If an extension set is used between the line 32 and the catheter C, thetubing volume is thereby increased and the above noted problems areexacerbated. If the system 10 is used without the pumps 21, 23 and 25the results become even less predictable.

FIG. 2 is a perspective view of a sealed multiple fluid flow deliverysystem 40 in accordance with the present invention. The system 40 issupported by framework 42 and contained within housing 44. Housing 44 ismounted on a plurality of casters 46 to provide easy movability of thesystem 40.

At an upper end 48 of the framework 42 is a curved supporting member 50.The member 50 supports a first set of hangers 52 and a second set ofhangers 54. The set of hangers 52 and the set of hangers 54 are used forthe purpose of hanging flexible solution containers such as theillustrated first plurality of solution containers 56 and theillustrated second plurality of solution containers 58.

The solution container 56a is one member of the plurality of containers56 which is to be replaced by the second plurality of containers 58 atthe end of a predetermined period of time, such as a 24 hour interval.Usually one of the pluralities of containers 56 or 58 at a time iscoupled into the system 40. The double set of hangers 52, 54 facilitateshanging the second, replacement, plurality of containers while the firstset continues to provide fluid to the patient.

Beneath the containers 56 and 58 is a generally horizontally extendingframework 62. The framework 62 supports, in spaced-apart relationship, aplurality of electrically actuated clamps or tubing occluders 64. Eachof the members of the plurality of occluders 64 is independentlyactuatable as is discussed subsequently.

Associated with the plurality of clamps 64 is a plurality of manuallyoperable, lightable actuators 66. One actuator from the plurality 66 isassociated with a corresponding member of the plurality of occluders 64.

Located beneath the member 62 and slidably affixed thereto are first andsecond fluid junction members 70 and 72. The members 70, 72 can be, butneed not be identical.

Linking the solution containers 56 or 58 to the fluid junction members70 or 72 are a plurality of fluid-flow conduit members 74 and 76. Eachof the members of the plurality 74 and the plurality 76 can be formed offlexible medical grade plastic, preferably transparent.

Each of the members of the pluralities 74 and 76 has a first connector,such as a spike connector which can be used to place the conduit influid flow communication with a respective fluid-flow container such as56a, and a second connector at a second end which can be used to placethe conduit into fluid-flow communication with the fluid-flow junction70 or 72.

It will be understood, as described in more detail subsequently, that asealed fluid-flow system is formed between the plurality of containers56, the plurality of conduit members 74 and the junction members 70 or72. Similarly a sealed system is formed with the alternate plurality offluid-flow containers 58, corresponding plurality of fluid-flow conduits76 and the junction members 70 and 72.

Each junction member 70 or 72 is coupled by an output fluid-flow member80, 82 respectively to a peristaltic pump 84 and 86. The pumps 84 and 86are illustrated in FIG. 2 with manually operable control panels 84A and86A respectively. Such control panels are a convenience but do not forma part of the present invention. The pumps 84, 86 are precise linearperistaltic pumps with a dead band at the end of each pumping cycle. Thetype of pump used is not a limitation of the present invention.

Extending from the pumps 84, 86 are output fluid-flow conduits 90 and 92respectively. The output conduits 90 and 92 terminate in a luerconnector or a piercing cannula and are intended to be coupled directlyto a patient's catheter. Such coupling would be in accordance withstandard aseptic technique. Upon completion of such coupling, witheither the output fluid-flow member 90 or the member 92 or both, asealed fluid-flow system is formed between the fluid flow sources 56 or58 and the patient P.

The system 40 also includes a video display 96 for the purpose ofdisplaying status and command information to a system operator orattendant. Information can be input to the system 40 via the display 96using the light pen of a combined light pen and bar code reader 98electrically coupled to the system 40.

Also coupled to the system 40 is a hard copy printer 100. The hard copyprinter 100 is especially useful for generating hard copy records ofregimes of fluids delivered to the patient P for inclusion in thepatient's chart or for purposes of auditing the fluid delivery to thepatient.

The hard copy printer 400 can be a spooling printer which contains anon-volatile random access memory. The system 40 can spool selectedinformation to the memory of the printer 100. In normal operation, thatinformation need not be printed.

In the event that a pre-selected condition is detected, that informationcould then be printed for analysis purposes.

FIG. 3 is an overall block diagram of the sealed fluid-flow circuitry ofthe system 40. Each of the containers, such as the container 56a iscoupled via a corresponding flexible conduit, such as the conduit 74athrough a corresponding occluder, such as the occluder 64a to thefluid-flow junction 70.

The output line 80 from the fluid-flow junction 70 passes through thepump 84. Output from the pump 84 via the output fluid-flow conduit 90 isthen coupled to the patient.

A control system 102 is electrically coupled to each of the members ofthe plurality of electrically actuated occluders 64, the pump 84, thevideo display 96 and the printer 100. The control system 102 includes aData In/Out port.

FIG. 4 illustrates in greater detail the fluid-flow circuitry of thesystem 40. In FIG. 4, container 56a is coupled to the tubing member 74a.The tubing member 74a terminates at a first end in a spike connector75a. A drip chamber 77a is carried by the tubing member 74a. The spikeconnector can be used to puncture the access port of the container 56aand as is well-known can also be a sterile connector.

The drip chamber 77a is useful for manually setting a rate of fluid fromthe container 56a should that be desirable. It is also intended to actas a barrier against air from container 56a entering the tubing member74a and it is also used as a means to observe that fluid flow from thecontainer 56a takes place. The tubing member 74a terminates at a secondend in a connector 75b of a type which can removeably and sealablyengage the fluid junction member 70. Other containers 56b, 56c or 56dare coupled to the junction member 70 using identical tubing members.

If it is desirable to couple more containers to the fluid junctionmember 70, as illustrated in FIG. 4, a second fluid junction member 70acan be coupled to the junction member 70. This coupling can beaccomplished by means of a tubing member 70b of a selected length or bymeans of a double-ended cannula 70c. The double-ended cannula 70c canpierceably engage both the junction member 70 and the junction member70a.

Another way is to have member 70 have its non-tubing end as a pierceableseptum and 70a have a cannula as one end. They can then be joinedtogether by piercing the end of 70 with the cannula of 70a. A third wayis to put two needles into a single septum. They are designed to accepttwo needles without leaking. When so coupled together, the containers56a-56g all drain into a single tubular output conduit 80.

Tubular conduit 80 has a region 80a which is designed to be insertedinto the pump 84 for the purpose of forcing fluid there through at apredetermined rate. Tubing section 90 includes a first "Y" junction is90a which is useable for withdrawing air or any other fluid from thecomposite output fluid. The output conduit 90 also includes a second "Y"junction 90b for the purpose of injecting additional fluids ormedication into the conduit 90 at a site very close to the patient P.

The tubular member 90 has a connection 90c, which can removeably engagea mainline catheter C. This type and location of siting on a patient isnot a limitation of the present invention. Catheter C has previouslybeen surgically inserted into the patient P. Since the "Y" connector 90bis located relatively close to the catheter C, additional fluids ormedications which are injected via the connector 90b will in a veryshort period of time be infused into the patient P.

In the fluid flow transfer set of FIG. 4, the tubing member 80 has anominal diameter on the order of 0.100 inches. The tubing member 90 hasa nominal diameter on the order of 0.065 inches. The smaller diameter ofthe member 90 minimizes the volume of fluid residing in the set betweenthe pump, such as the pump 84 or 86, and the patient P. When flushingthe line 90, the smaller diameter means that less flush will be needed.

FIG. 5A is a perspective view of the fluid-flow junction member 70.Junction member 70 includes a housing portion 100 which is formed withspaced apart elongated sides 100a. Sides 100a terminate in a planarshield member 100b. As will become more apparent subsequently, when theelongated side members 100a are being gripped manually, the shieldmember 100b provides protection to the manually gripping fingers of theattendant.

The elongated side members 100a also terminate at an end surface 100c.Affixed to the surface 100c are mounting members 102. Mounting members102 slidably engage slots or openings at the base of the panel 62 forthe purpose of removably mounting the fluid junction member 70 on thesystem 40.

Located on the protective shield 100b are a plurality of sealed inputports 104a and 104b. Each of the fluid input ports, such as a typicalport 106 is formed with a cylindrical housing 108. The housing 108extends at an angle from a housing 109 in the plurality 104b.

A pierceable septum 110 is surrounded by the housing 108. The septum 110is formed of pierceable rubber of a type which is known to reseal itselfupon removal of a piercing cannula. The septum 110 provides a continuoussealed region through which sterile fluids may be injected into thejunction member 70.

The members of the plurality of access ports 104a are each orientedabout an axis of rotation which is at a 45 degree angle to the axis ofrotation of members of the plurality of input ports 104b. In addition,the members of the plurality 104a are staggered and spaced between themembers of the plurality 104b.

Each of the ports in the pluralities 104a and 104b can be covered by aremovable cap 111. The cap 111 can protect the septum and keep itsterile. Covering the ports provides a continuously sterile septum, suchas the septum 110 which need not be wiped with a disinfectant prior touse.

The offset and angular orientation of the ports 104a and 104b is for thepurpose of ease of attachment of the conduit members 74 illustratedschematically in FIG. 4.

With reference to FIG. 5B, the housing 100, shown in section defines aninternal flow path 112 which has a generally circular cross section. Acannula 114 which is affixed to the connector 75b can be insertedthrough a sterile septum, such as a septum 110 and into the region 112.Fluid can then flow from the container 56a through the tubing member 74aand into the central region 112 of the junction member.

Fluid can then flow from the junction member 70 through the tubingmember 80 to the patient. As illustrated in FIG. 5B, the use of thepierceable septum, such as the septum 110 provides for a continuouslysealed system for fluid flow between the source, such as the container56a and the patient P. Removal of the cannula 114 from the septum 110closes the junction member 70 as the rubber seals the access portcreated by the cannula 114.

It should be noted that the fluid junction member 70 is always open forreceipt of and flow of fluid therethrough. The junction member 70 doesnot function as a mixing chamber. Rather, the junction 70 provides onlya junction such that a plurality of different fluids from a plurality ofsolution container such as 56a-56d can sequentially flow into the outputtubing member 80.

In accordance with the present invention, the thickness of each septum,such as the septum 110 is on the order of 0.25 inches. The thick septumprovides a wiping action on insertion of the piercing cannula 114 tofurther block entrance of any contaminating agent into the closedsystem.

In addition, the thickness of the septum 110 will support 2 or 3inserted cannuli without tearing or leaking. The added thicknessprovides that the septum 110 may be pierced more than once in a 24 hourperiod, and still continue to properly reseal on removal of the piercingcannula.

The shield 100b is especially useful in connection with inserting thecannula 114 into the septum 110 in that the person inserting the cannulacan manually grip the housing sides 100a without fear of jabbinghimself/herself with the cannula 114 since a reasonable amount of forceis required to insert the cannula through the thick septum 110.

Affixed to an end of the housing 100 is a septum 110a. The septum 110acan be used for the purpose of joining together two junction memberssuch as 70 and 70a illustrated in FIG. 4.

The dimensions of the channel 112 are made as small as possibleconsistent with fluid flow from the inserted cannuli into the outputtubing member 80. As a result, the junction member 70 at any one timecontains a very small volume of fluid. This minimizes inter-fluid mixingin the junction member 70.

It will be understood that the channel 112 could be formed with otherthan a circular cross section. The exact shape of the channel 112 is nota limitation of the present invention. Further, it will be understoodthat while the pluralities of injection sites 104a and 104b have eachbeen illustrated in FIG. 5A with an axes of rotation offset from theother to facilitate independent accessability to each site, the exactorientation of the injection sites with respect to one another is alsonot a limitation of the present invention.

FIG. 5C illustrates an alternate embodiment 120 of the junction member.The junction member 120, in contradistinction to the junction member 70,is formed with luer twistlock connectors 122. Each of the inputfluid-flow conduits, such as the conduit 124 carries a matching luerconnector member 124a which can engage the member 122 permanentlyaffixed to the junction member 120. It will be understood that prior tocoupling the tubing member 124 to the junction member 120, the luerconnector 122 would be sealed with a removable luer lock cap.

As an alternate to the luer connector 124a, a luer connector 126 with aseptum could be used. In this instance, a tubing member, such as thetubing member 74a with the piercing cannula 114 could be used. Theconnector 126 could also be sealed with a removable cap 127.

FIG. 5D illustrates yet another variation of the junction 70. A tubingmember 128 is coupled to the flow path 112. A free end of the tubingmember 128 carries a spike connector 128a. The connector 128a can beused to couple a container of a flush solution to the junction 70.

FIG. 5E is a view of yet another junction member 130. The junction 130has an elongated housing 132 with a flow path 132a therethrough. Aplurality of ports 134, with members offset from one another, is alsoprovided. A shield 136 protects the fingers of an operator inserting acannula into one of the ports 134 and can also be used as a spring likeplate to facilitate the mounting of the junction to a hold bracket. Thefoot member 102a is a continuous member.

As illustrated in FIG. 5F, the input ports 108 can each be formed havinga circular cross section 110b. A plurality of capillary spline grooves110c can be spaced about the periphery of the circular cross section110b. The groves 110c provide a means for inflowing fluid to displacethe entrapped air in the input ports 108, or prime, when a liquid isinitially introduced into the system.

FIG. 6 is a block diagram of a control system 142 usable with the fluiddelivery system 40. The control system 142 includes a main processorsystem board 144. The board 144 includes 80C88 and 80C87 programmableprocessors. The system board 144 also includes 640 kilobytes of randomaccess memory, 64 kilobytes of read only memory, a graphics controller148 to drive the monitor 96 and various input-output circuitry. Coupledto the main processor system board 144 is a pump and occluder interface999.

The interface 999 includes as a secondary processor an 80C88programmable processor 999a. The interface 999 also includes an occluderor clamp interface 999b along with EPROM and DRAM memory 999c and atimer counter 999d. The pump and occluder interface 999 also includesfour microcontrollers 999e which communicate with and control thefunction of pump 84, pump 86 and two optional remote pumps 997 and 998.

The occluder interface 999b is electrically coupled to occluder drivecircuitry 152 which is located adjacent the supporting frame 62. Thecircuitry 152 includes a plurality of drive circuits, such as the drivecircuit 152a. Each drive circuit is associated with a particularoccluder such as the occluder 64a.

Each occluder has associated therewith a multielement position sensor 67which provides feedback via the occluder interface 999b to the processor999a. The sensors 67 can be switches, photo-optical or other non-contactposition sensors such as capacitive or inductive sensors.

A general purpose interface 146 is coupled to the system board 144through the bus interface 146b and provides input/output capability.Included are a barcode micro-controller 146a and its associated lightpen/bar code reader wand 98; a tone generator 146e and associated audiospeaker 150; a power and temperature monitor 146f; a remote nurse calland warning light circuitry 146g; modem interface circuitry 156; a realtime clock 146d; 4 Kb RAM battery backup memory 146h; and a watchdogtimer to sense timing error 146i. To provide additional input-outputcommunication facilities, the general purpose interface 146 includes amulti-channel RS232 interface 154.

Power to the system 40 is supplied via a power supply 160 which operatesoff of standard AC power lines and in turn charges a 24 volt battery 162to permit the unit 40 to continue operating when being moved from onelocation to another. A typical battery could be an Eagle PicherCFM24V25AH. Battery voltages available to the system 40 include ±5 V,+6.5 V ±12 V, +24 V, +27.5 V.

FIG. 7 is a block diagram schematic of the interface circuitry 152associated with each of the occluders 64. The interface circuitry 152includes, for each occluder, a command or output register 166, afeedback buffer 168 and control circuits 170. Data and control signalsare transmitted between the occluder interface 999b and the interfacecircuitry 152 via a communication bus 152b.

The occluder driver 152a is actuated by setting a bit in the commandregister 166. The set bit on a line 152c, provides an input signal tothe driver 152a. Output from the driver 152a powers a solenoid coil 172to open the corresponding occluder.

Another bit in the output register 166 can be set to turn the occluderindicator 67a on and off. The set bit on a line 152d and an associatedbuffer drive power the indicator 67a. The indicator 67a can becontinuously on or can blink if desired.

Feedback inputs to the interface circuitry 152 include the manualsolenoid override switch 67b and a three position, multi-pole sensingswitch 67c. Depression of the switch 67b can cause the occluder 64a tobe energized for removal or insertion of a section of tubing.

The three position sensing switch 67c provides feedback to the interfaceas to the status of the occluder. Pole S1 is normally closed when theoccluder is in its closed or unenergized position. Pole S2 is normallyopen and closes in an intermediate condition of the occluder. Pole S3 isnormally closed indicates on opening that the occluder is fullyenergized and open permitting fluid flow.

The solenoid driver 152a applies a suitably high voltage and current soas to magnetize the airgap present when the occluder plunger is in itsfirst or closed position. When the plunger has moved to its second oropen position permitting fluid flow, which takes about 25 milliseconds,the voltage and current to the coil 172 is reduced. This second level ofelectrical energy is sufficient to maintain the occluder in its secondor fluid flow permitting position, but yet minimizes heating of the coil172 and minimizes drain from the battery 162.

When the coil 172 is deenergized, a coil spring pushes the occluder 64ato the closed position with a force of the order of 4 pounds. Theinitial voltage applied by the driver 152a is on the order of 16 volts.

FIG. 8 illustrates the structure of the electrically actuated occluder64a. The other occluders have an identical structure. Occluder 64aincludes the electrically energizable solenoid coil 172 which surroundsa movable plunger 174. The plunger 174 is movable in a direction 176under the influence of the magnetic field generated by the coil 172 froma first, fluid flow blocking position to a second fluid flow enablingposition illustrated in FIG. 8.

A tubing clamping member 174a is carried by the plunger 174. When theoccluder is not energized, the clamping member 174a blocks fluid flowthrough the inserted tubing member 74a. An actuating rod 176a alsocarried by the plunger 174 opens and closes switch contacts S1, S2 andS3 as the plunger moves.

A biasing spring 178 forces the plunger 174 to return to its firstposition upon removal of electrical energy from the coil 172. A manuallydepressable knob 177 is provided to manually move the plunger 174 awayfrom the tubing 74a.

The position sensor 67c is carried by a bracket 179a which is supportedby the housing 179b of the solenoid 64a. The position sensor 67c isimplemented as a three contact mechanical switch assembly. The threecontacts S1, S2 and S3 provide position information to the circuitry 152for various possible positions of the clamping member or plunger 174.

The first position corresponds to the occluder 64a being deenergizedwithout any tubing having been inserted. In this condition S1 and S3 areclosed and S2 is open. The second position corresponds to the positionillustrated in FIG. 8 with the plunger 174 moved to its fully openposition permitting fluid to flow through the tubing member 74a. In thiscondition S1 and S3 are open and S2 is closed.

The third position is a test position which is intermediate between thefirst two positions indicating that the plunger 174 is stuck part of theway between its first or fully closed position and its second openposition, as illustrated in FIG. 8. This indicates that the plunger 176is not in the desired open or closed position. Here S1 is open and S2and S3 are closed. The presence of tubing 74a in the occluder isindicated if S1 and S2 are open but S3 is closed.

The occluder 64a also includes a plurality of fluid resistant seals.Diaphram seal 180a, 180b, an annular seal and band compression and 0ring seals 180c block incident fluids from entering the occluder and itsassociated electrical and electronic components housed in the framework62.

"O" ring 180d provides sound muffling on opening when the plunger 174moves in the direction 176. The tubing member 74a cushions the plunger174 on closure.

With respect to FIG. 9A, the solenoid drive circuit 152a includes anintegrated drive circuit 184 which could be implemented as a L295integrated circuit manufactured by SGS-Semiconductor Corporation.Outputs from the drive circuit 184 via lines 172a and 172b are coupledto the solenoid coil 172. The drive circuit 152a is typical of those inthe system 40. Each drive circuit is associated with a differentoccluder.

Input to the drive circuit 184 on the line 152c is a five volt or groundsignal. The drive circuit 152a energizes the solenoid coil 172 wheninput signal on the line 152c is on the order of five volts.

Voltage divider resistors 186a, 186b and 186c are connected at a node186d to form a reference voltage input at pin five of the circuit 184.At a node 186e the normally closed contact S3 provides a return path toplus five volts except when the plunger 174 has moved to its fully openposition.

A parallel resistor combination including resistors 188a and 188b formsa 0.5 ohm current sensing resistor which is in series with the load.

The drive current to the solenoid coil 172 is set by the value of thevoltage at the node 186d of the drive circuit 184. With the parallelresistor values 188a and 188b set to provide 0.5 ohm to ground, thecircuit 184 is calibrated to provide 2 amps of current to the coil 172for each one volt of input at the node 186d.

The indicated values of the resistors 186a, 186b and 186c are chosen toprovide 0.6 volts at the node 186d. The drive circuit 184 supplies 1.2amps of pull-in current to the solenoid coil 172 until the plunger 174reaches its fully open position and opens the switch contact S3. When S3opens, the voltage at the node 186d is set by the combination of 186a,186b and 186c and is reduced to 0.2 volts. The driver circuit 184 thensupplies 0.4 amps of holding current to minimize power consumption.

In FIG. 9B, a graph of voltage across the solenoid 172 versus time isplotted for a 13.5 ohm solenoid coil. In this case only 16.2 V of theavailable 24 V supply is applied by the drive circuit 184. The pull-inand holding currents can be adjusted by changing the values of theresistors 186a, 186b, 186c as well as the sensing resistors 188a and188b. In the graph of FIG. 9B, the indicated time to corresponds to thetime when the switch contact S3 opens. At that time power to thesolenoid coil 172 is reduced from a pull-in value to a holding value.

FIGS. 10A-10C together form a flow diagram illustrating representativeoperator initiatable functions or actions which can be undertaken inconnection with the system 40. As illustrated in FIG. 10A in a step 200,a Main Menu can be displayed on the display unit 96. Prior to displayingthe Main Menu, if desired, a menu could be displayed for the purpose ofcalibrating the light pen 98. Operator displayable screens are includedherein in an attached Addendum.

The Main Menu is illustrated on Screen 1. For reference purposes, linemembers are printed along the left side of the screen. At the top ofScreen 1, on line 2 a patient's name and identification number(previously entered) as well as date and time can be displayed. On line4, previously selected pump A or pump B, corresponding to pump 84 orpump 86 can be displayed in combination with a previously selectedoccluder as well as a fluid delivery rate.

Between lines 7 and 19 of Screen 1, members of a plurality of operatorselectable actions are identified. For example, with respect to line 7on Screen 1, the operator can select a change of pump rate. Alternatelythe operator on line 7 could choose to ask for the IV schedule.

With respect to line 9, the operator can invoke the procedures for IVorder entry or call for the list of discontinued orders.

On line 11, the operator can invoke the procedure to change existing bagor ask for patient information.

On line 15, the operator can invoke the procedure for vital signs/weightentry or, ask for system IV (volume) totals.

On line 17, the operator can invoke the procedures for new patientinstallation or, ask for a list of call back messages.

On line 19 of screen 1, the operator can ask for an index of screens andprocedures, or, invoke the procedures for system installations andtests.

On lines 22 and 24 of the Main Menu a variety of standard functions isprovided which can be selected by the operator. For example, on line 22the operator can select to MUTE the system alarm. Additionally, theoperator can select to view system PUMP DISPLAY, to EDIT IV ORDERSscheduled previously or to display a KEYBOARD overlay.

On line 24, the operator can implement a PAUSE function, a selection ofdrug specification through the DRUG MASTER screen sequence, or canrequest a HELP screen. Specification of an action or a function iscarried out by the operator using the light pen 98.

It will be understood that while the screens illustrated herein are in aform suitable for printing as textual information that the invention isnot limited to such screen formats. For example, various selectableactions or functions can be displayed in reverse video should that bedeemed to facilitate operator interaction. In addition it will beunderstood that if desired a selected function or indicia of actioncould be caused to blink, before or after selection, to provide visualfeedback to the operator of what has been selected.

For exemplary purposes, assuming that the operator selected the NEW IVORDER function, line 22 of Screen 1, the system 40 would immediatelydisplay Screen 2. FIG. 10B illustrates a sequence of steps associatedwith this function.

Line 2 of Screen 2 again displays the patient's name and identificationnumber. Lines 22 and 24 display the same set of functions as werepreviously displayed on those lines on Screen 1. On line 4 of Screen 2the same pump, occluder and rate information is again displayed as wasdisplayed on line 4 of Screen 1.

Line 7 of Screen 2 indicates specification of a drug/dose. The drugpotassium chloride with a dose of 20 MEQ has previously been entered.When Screen 2 first appears, the "DRUG/DOSE" identifier can be displayedin blinking form to indicate the first entry. The operator can carry outa drug/dose entry by first selecting a displayable keyboard. This isaccomplished by selecting the keyboard function on line 22 in a step202. When so selected, a keyboard screen, Screen 3 appears on thedisplay 96.

Drug names can be entered using the alphabetical portion of the keyboardon Screen 3 in lines 10-14. The light pen is used for selection of eachcharacter in a step 204. The operator selects a sequence of alphabeticalcharacters, each of which appears on line 8 of Screen 3 after it hasbeen selected. In addition, a numeric drug dose can be selected from thekeypad at the right side of the keyboard screen in units assigned fromthe units indicated on lines 18 and 20 of Screen 3.

After a drug and dosage have been entered, the operator in a step 206then selects the ENTER function on line 17 of Screen 3 using the lightpen 98. Upon sensing a selection of the RETURN function, the system 40then returns to Screen 2 with the entered drug and dosage informationdisplayed on lines 7-9.

The operator in a step 208 can then select one of a group of standardsolutions from line 10 of Screen 2. To assist the operator, the"SOLUTION" designator can also blink. After a solution has beenselected, the "RATE" designator can be caused to blink by the System 40.

The operator can then in a step 210 specify the KEYPAD function fromline 20 of Screen 2. A keypad overlay, illustrated in Screen 4, is thendisplayed on the right hand side of display 96. Numeric rate of deliveryinformation on line 10 of Screen 2 and dosage volume information on line13 of Screen 2 can be entered in a step 212. In addition, the operatorcan enter, with respect to line 13 of Screen 2, the total number ofdoses to be administered.

The operator can then select in a step 214 one of a group of standardcontainer or bag volumes from line 12 and can specify type of usage fromline 14. Types of usage can include intermittent, INTER; continuous,CONT; flushing, FLUSH; keep vein open, KVO; or a combined flush/keepvein open function, FLUSH/KVO.

Again with respect to Screen 2, the operator in a step 216 can thenenter scheduling information on line 16 to specify how often the drug orsolution is to be provided. Completion of the order is indicated by theoperator selecting the ENTER ORDER function in a step 218 on line 20.

Should it be desirable at this time to enter and schedule an additionaldrug or solution the operator would repeat the above described processagain using Screen 2. Once all of the desired drugs or solutions havebeen specified the operator can in a step 220 specify the NEXT SCREENfunction from line 24. This will then cause the system 40 to displayScreen 5 the IV Fluid Review and Edit Screen.

On Screen 5, lines 7, 8 and 9 three entered drug types and dosages aredisplayed. To the right of the displayed drugs is an assigned pumpcolumn labeled "P" and an assigned occluder column labeled "OC". FIG.10C illustrates the steps associated with using this Screen 5.

Each of the drugs has been assigned as illustrated on Screen 5 to thesame pump A which can be either pump 84 or pump 86. Each of the drugshas been assigned to a different occluder.

Assignment of pumps and occluders to previously entered drugs can becarried out by the operator. The operator requests in a step 230 aPUMP/OCCLUDER function located on the right end of line 7. When thesystem 40 senses this request, Screen 6 a keypad for pump and occluderselection is displayed overlaying the right side of Screen 5.

The first drug, on line 7 of Screen 5, can be highlighted for example inreverse video. Using the pump and occluder keypad overlay, a pump can beassigned to that drug along with an occluder in a step 232. Using theSCROLL function, line 20 on Screen 5, each of the drugs on lines 8, 9can be selected in turn. In a similar fashion each of the drugsdisplayed on lines 8 and 9 can then be assigned to a pump and anoccluder.

The system in a step 234 will automatically suppress the pump andoccluder key pad overlay Screen after selections are complete. Toinitiate infusing, the operator in a step 236 can then select the INSERTTUBING function on line 9 of Screen 5.

Subsequent to the system 40 sensing that the INSERT TUBING function hasbeen selected, one of the occluder indicators, such as the indicator67a, which corresponds to occluder 64a will start to flash. This alertsthe operator to insert the tubing for the selected drug or solution intothat occluder. This can be accomplished by the operator depressing theOCCLUDER OPEN/CLOSE switch, such as the switch 67d. The system 40 willthen energize the corresponding occluder, such as the occluder 64a,which will permit insertion of the tubing associated with the selectedsolution container into the occluder.

Depressing the OCCLUDER OPEN/CLOSE switch, such as the switch 67d, asecond time notifies the system 40 that the tubing has been positionedin the occluder and the occluder can then deenergized. Each of theremaining occluders can be activated and loaded with a correspondingtubing member in a similar fashion. At this time infusion of thescheduled drugs can be initiated.

In the event that the operator wishes to check interfluid compatibilityof those fluids and drugs listed on Screen 5, prior to initiatinginfusion it is only necessary to select the COMPATABILITY function fromline 19 of Screen 5.

The system 40 will then display a Compatibility Summary, with respect tothe three drugs previously listed on Screen 5, as illustrated by Screen7. In the Compatibility Summary of Screen 7, the three previouslyentered drugs are listed on lines 7, 8 and 9.

Near the center of Screen 7, each of the drugs, identified as drug 1,drug 2 or drug 3, is compared to each of the other two drugs. Forexample, as indicated on line 7, potassium chloride, drug 1, whencompared with Tobramycin, drug 2, results in an indicia "C" beingdisplayed. The indicia "C" indicates that those two drugs arecompatible. On the other hand, a comparison of potassium chloride, drug1 with Flagyl, drug 3, indicates an incompatibility.

In order to deal with the incompatibility between the potassium chlorideand the Flagyl, the potassium chloride can be assigned to one of the twopumps and the Flagyl can be assigned to the other of the two pumps. Thismultipump assignment is illustrated near the right side of Screen 7 in acolumn with a heading "P". To facilitate pump assignment and occluderassignment a pump occluder keypad is displayed along the right side ofScreen 7.

It should also be noted in Screen 7 that, a FLUSH function is providedon line 20. A flush can be provided both before and after delivery ofany selected drug or fluid.

With respect to the Compatibility Summary of Screen 7 it will beunderstood that drug or solution compatibility or incompatibilityinformation can be prestored in the nonvolatile memory 146c. That memorycan be updated or its contents modified from time to time depedding onthe solutions or drugs being used with the system 40. A blank columnindicates a lack of information.

Subsequent to initiating infusion, a Medication Summary, Screen 8 can bedisplayed. Screen 8 provides an identification of scheduled drugs, forexample on lines 7, 8 and 9. Additionally, Screen 8 identifies theassigned pumps and occluders along with an indication of scheduledfrequency of delivery of the drug or solution. In the right hand portionof Screen 8 a representation of time intervals of delivered drugs duringa twenty-four hour period is displayed with quarter hour increments.

The SCROLL functions can be used to move the display through thecomplete 24 hour time period.

If a hard copy of the Medication Summary is desired, on line 20 anoperator can select a PRINT SUMMARY function which causes the system 40to then create a hard copy of the summary.

It is also possible for an operator to display in various alternateforms the status of scheduled solutions being infused to the patient P.For example, the system 40 provides a Drug Status Display, Screen 9.

In Screen 9 an example of a different set of drugs is identified alongwith its related solution. For example, on lines 8 and 9 dopamine anddextrose have been identified as being delivered via occluder 4. Furtherto the right on lines 8 and 9, a delivery rate is specified as well as atotal previously infused volume and a remaining volume yet to beinfused. Comparable information is provided for drugs and solutionsassociated with each of the other occluders, such as occluders 5, 6 and7 which are associated with the same pump.

The system 40 can also assist a health care provider in fluidmanagement. In this regard, Screen 11 provides for forecasting ofexpected intake volumes of fluids. Line 7 of Screen 11 provides forentry of a maximum fluid volume over a 24 hour period.

Between lines 9 and 18 a display is provided of currently committedfluid quantities, based on 8 hour time periods. Additionally, a displayis provided of currently available quantities of fluids which can beadded to those quantities already committed during each 8 hour timeperiod. Hence, Screen 11 provides 8 hour projections as well as dailytotals with respect to both volumes of committed fluids and currentlyavailable volumes of fluids.

In the prior discussion, the system 40 could be operated in a modewherein one solution at a time was to be infused into the patient P. Forexample, with respect to Screen 5, potassium chloride was to be infusedcontinuously. Tobramycin was to be infused intermittently. During thetime that tobramycin was being infused, via occluder 2 the potassiumchloride would be blocked from flowing via occluder 1.

In an alternate mode of operation, two or more fluids and drugs could besimultaneously infused into the patient P. In the prior art,simultaneous infusion of multiple drugs utilized systems of the typeillustrated in FIG. 1A with results of the type illustrated in FIG. 1B.

FIG. 11A illustrates schematically the system 40 coupled to a patient Pwhere 3 containers 56a, 56b and 56c have been coupled to the fluid-flowjunction member 70. In accordance with the present invention, thecorresponding electrically actuated occluders 64a, 64b and 64c aresequentially opened and closed to permit fluid flow of pulses or quantaof corresponding fluids from the containers 56a, 56b and 56c through theconduit members 74a, 74b and 74c in a predetermined sequence. In thismultiplexing mode, a fluid flow composed of a sequence of discretepulses or quanta of fluids from the containers 56a, 56b and 56c isformed in the output tubing member 90.

The same order of fluids is to be delivered by the system of FIG. 11A aswas previously to be delivered with the system 10 of FIG. 1A. That is,20 ml/hour of fluid 1, 20 ml/hour of fluid 2 and 50 ml of fluid 3 at 100ml/hour.

With reference to FIG. 11B, and in contradistinction to the graphs ofFIG. 1B, fluid 3 from the container 56c, which is to be provided at a100 ml rate to the patient for a 30 minute period, as illustrated at thetop most graph of FIG. 11B is initially started at the 15 minute pointwith a flow rate of about 30 ml per hour. Simultaneously, the flow ratesfor fluids from containers 56a and 56b have been substantially reducedfrom 20 ml per hour each to about 10 ml per hour. During the 15-30minute time interval as illustrated in the bottom graph of FIG. 11B,fluid flow to the patient P continues unchanged at 20 ml per hour ofeach fluid.

At the 30 minute point, the flow rate for fluid 3 from the container 56cis increased by the system 40 to 100 ml per hour. This flow rate ismaintained until the 55 minute point has been reached. Note that theorder, as was the case with the order of FIGS. 1A and 1B calls for 100ml of fluid 3 to be delivered to the patient P for 30 minutes.

As illustrated in the lower graph of FIG. 11B, output to the patient Pfrom the line 90 corresponds to 100 ml of fluid 3 for 30 minutes.Notwithstanding the fact that fluid 3 flow from the container 56c hasterminated at the 55 minute point, flow to the patient P of fluid 3continues to the 60 minute point at the prescribed flow rate. Also,during the time period 55-60 minutes, the rate of flow of fluids 1 and 2has been substantially increased to 70 ml per hour for each fluid asillustrated in the middle graph of FIG. 11B. However, output to thepatient P of fluids 1 and 2 as a result of the multiplexing of thepresent system continues at a 20 ml per hour rate.

Thus the system 40 has delivered exactly the prescribed fluidcombination, fluid 1 at 20 ml per hour, fluid 2 at 20 ml per hour andfluid 3 at 100 ml per hour for 30 minutes. In contradistinction, asillustrated in FIG. 1B the prior art stacking system of FIG. 1Adelivered a substantially different fluid flow to the patient.

In connection with the multiplexing mode of operation, the detailedsequence for entry of the various drugs or solutions could be the sameas the procedure discussed above for multiple drug delivery. The system40 has the capability of automatically multiplexing drugs assigned to apump if one or more of the drugs which has been assigned is to beinfused continuously and one or more of the drugs is to be infusedintermittently. In addition, a flush may be assigned to the pump thatwill be carrying out the multiplexing.

To check the status of the multiplexing operation, the operator candisplay Screen 12. On lines 8 and 9 of Screen 12 the drug dopamine inthe solution dextrose are being infused through occluder at a 30 ml perhour rate. In lines 11 and 12 of Screen 12 the drug aminophylline indextrose is being infused through occluder 5 at a 15 ml per hour rate.On lines 14 and 15 of Screen 12 the system 40 has indicated that thefluid Heparin is being infused to the patient through occluder 6 at a 25ml per hour rate.

In those instances where an intermittent drug, such as fluid 3 of FIG.11A has been scheduled during the multiplexing of continuous drugs, suchas fluids 1 and 2 of FIG. 11A, the system 40 will automatically predictwhen the infusion of fluid 3 should be initiated or terminated such thatthe output to the patient corresponds to the ordered fluid flowsequence. With respect to FIG. 11B, if the 30 minute time period is apoint at which the fluid 3 should be reaching the patient at a 100 mlper hour rate, prior to that time period the system 40 will determine anintermediate time period wherein the fluid 3 should be permitted to flowinto the output tubing 90 which is coupled to the patient.

As a result of this prediction by the system 40, during the intermediatetime period prior to the 30 minute period fluid 3 will began flowing.However, there will be no delivery of fluid 3 to the patient until the30 minute time period when the system 40 switches from its originalschedule of equal quantities of only fluid 1 and fluid 2 to the requireddelivery schedule of equal flow rates of fluids 1 and 2 and asubstantially greater fluid flow rate of fluid 3.

FIG. 11C is a graph illustrating the fluid aspects of the multiplexingof the system 40. The graph of FIG 11C corresponds to the multiplexingoperation with respect to the order to be delivered to the patient inthe lower graph of 11B.

With respect to FIG. 11C, fluids 1 and 2 are initially each alternatelypermitted to flow into the fluid flow junction 70 by respectiveoccluders for approximately 11 and 1/2 seconds. During this initialphase which corresponds to a time period of 0 to about 15 minutes thereis a steady state condition established wherein an 11 and 1/2 secondlong pulse or bolus of fluid 1 is permitted to flow into junction 70.Immediately thereafter an 11 and 1/2 second long bolus or pulse of fluid2 is permitted to flow into the fluid flow junction 70.

This process continuously repeats itself for the first 15 minutes duringthe initial phase of operation of the system 40. During this timeinterval the spaced-apart pulses or quanta of fluid 1 which enter line90 at an entry port 90a are spatially positioned between spaced-apartquanta or pulses of fluid 2. As the quanta of fluids 1 and 2 movethrough the tubing member 90, they are mixed together such that whenthey arrive at an output port 90b at the catheter C of the patient auniform mixture is delivered to the patient 50% of which corresponds tofluid number 1 and 50% of which corresponds to fluid number 2.

Prior to the 15 minute point, the system 40 has determined that it willbe necessary to initiate flow of fluid 3 so as to minimize fluidtransients to the patient and so as to deliver the ordered fluids at therequired flow rates. During this compensation phase or interim phasewhich extends from about the 15 minute point to the 30 minute point atwhich the fluid 3 should be delivered to the patient at a rate of 100 mlper hour, the system 40 is sequentially actuating each of the occludersassociated with containers 56a, 56b and 56c. The result of thisactuation, as illustrated in FIG. 11C, is to continue to provide fluids1 and 2 in 11.5 second quanta but after fluid 2 to inject a 57.5 secondquantum of fluid 3, via occluder 54c, into the fluid flow junction 70.

This three fluid multiplexing operation is continuously repeated fromthe 15 minute time point the 30 minute point. This results in a sequenceof spatially spaced apart quanta of fluids 1, 2 and 3 moving into theconduit 90 at the input port 90a. By the time the sequence of quanta offluid 1, sequence of quanta of fluid 2 and the sequence of quanta offluid 3 arrive at the output port 90b they will be mixed and provide acomposite fluid flow output rate at a 140 ml per hour rate with fluid 1being provided at a 20 ml per hour rate, fluid 2 being provided at a 20ml per hour rate and fluid 3 being provided at a 100 ml per hour rate.

At the 30 minute point, the system 40 will again switch. At the 30minute point, the fluid flow rate jumps to 140 ml per hour. At thistime, fluid 1 is permitted to flow at approximately for a 3.3 secondinterval, fluid 2 is permitted to flow for a 3.3 second interval, andfluid 3 is permitted to flow for a 16.4 second interval. This sequenceis repeated for 25.6 minutes which corresponds to a time of 55.6minutes.

Prior to the 55.6 minute point, the system 40 will have predicted thatit will be necessary to terminate flow of fluid 3 from the container56c. A second compensation phase will be needed. Hence, at that timeoccluder 64c will be de-energized and flow of fluid 3 from the container56c ceases. However, flow of fluid from the containers 56a and 56bcontinues during the time interval between 55.6 minutes and 60 minutesat a rate of 140 ml/hour.

In this second compensation phase, fluid 1 is permitted by occluder 64ato flow for 3.3 second time intervals. Similarly, fluid 2 is permittedby occluder 64b to flow for 3.3 second time intervals. Hence, duringthis compensation phase alternating pulses of fluid 1 and fluid 2 arepermitted to enter the fluid flow junction 70 and exit to the input port90a of the conduit 90. As the spatially spaced apart quanta of fluid 1which are interspersed between the spatially spaced apart quanta offluid 2 move through the conduit 90 they are mixed and arrive as astream of 50% fluid 2 at the output port 90b.

At the time equals 60 minute point, the fluid flow rate drops to 40 mlper hour and fluids 1 and 2 continue to be sequentially injected intothe fluid flow junction 70 for 11.5 second long time intervals. Thisthen results in an output fluid flow to the catheter C at a rate of 20ml per hour for each fluid.

In further illustration of the multiplexing process, FIG. 12 is aschematic diagram of a plurality of spaced apart quanta of fluid one,each bearing an identification numeral of F1. Interspersed between thequanta of fluid one is a spaced apart sequence of quanta of fluid twoeach bearing an identification numeral F2.

The spaced-apart sequence of quanta of fluid one and the interspersedspaced apart sequence of quanta of fluid two enter the tubing member 90at the input port 90a. The quanta are mixed while in the tubing member90 and at the output port 90b is a fluid flow at a designated rate whichincludes fluids one and two in equal proportions.

It will be understood that the process of predicting when the system 42should switch from a first predetermined flow sequence to anintermediate or compensating flow sequence and then to a secondpredetermined flow sequence is dependent on the volume of the tubingmember 90. For purposes of the following discussion the tubing member 90shall be assumed to be equal to 10 ml.

The present multiplexing system compensates for effective flow rateerrors which occur when a solution's flow rate is changed. Whenoperating in the multiplexing mode, the system 40 can simultaneouslydeliver a plurality of drugs and solutions with one infusion pump.

The effective flow rate of each drug at a given time is equal to thefraction of the drug in the tubing times the initial total (or pump)flow rate. For example, if the tubing 90 is filled with a mixture of 1/4drug A and 3/4 drug B and the pump rate is 100 ml/hr, then the effectiverate of drug A is 25 ml/hr and the effective rate of drug B is 75 ml/hr.

During steady state, the effective flow rate of each drug is the same asthe desired rate. The rate errors occur when the pump rate is changed toa new rate, but the drugs in the tubing are mixed in proportion to theprevious rates. This causes the effective flow rate of each drug to bein error until the tubing is flushed by the drugs running in the newproportion.

For example, assume that drug A is running at 20 ml/hr with drug B at 60ml/hr. The total rate is 20+60=80 ml/hr. The tubing 90 contains20/80=1/4 A and 60/80=3/4B.

If the rate of A is changed to 40 ml/hr, the total flow rate is40+60=100 ml/hr. The effective rates are now 1/4*100=25 ml/hr for A, and3/4*100=75 ml/hr for B. The errors are 100*(25-40)/40=-37.5% for A, and100*(75-60)/60=25% for B.

These effective flow rate errors will continue until the tubing 90 hasbeen flushed. If the tubing volume is 10 ml, then flushing it will take10 ml /100 ml/hr=0.1 hr=6 minutes. After the tubing is flushed, theeffective rates will equal the desired rates.

In summary:

    __________________________________________________________________________    Effective flow rates (ml/hr):                                                             A       B      Total                                              __________________________________________________________________________    Initial     20      60      80                                                Transition  25      75     100                                                Final       40      60     100                                                __________________________________________________________________________    Transition calculations:                                                             A              B                                                       __________________________________________________________________________    Tubing mix                                                                           20/80 = 0.25   60/80 = 0.75                                            Effective rate                                                                       0.25*100 = 25 ml/hr                                                                          0.75*100 = 75 ml/hr                                     Rate error                                                                            ##STR1##                                                                                     ##STR2##                                               __________________________________________________________________________

The system 40 automatically determines and inserts an intermediate orcompensation phase between the Initial and the Final flow rates whencarrying out the multiplexing function. This compensation phase is usedto adjust the individual drug rates, in order to properly proportion thedrugs in the tubing in preparation for the new flow rates.

The compensation phase is initiated ahead of the next scheduled flowrate change by the amount of time required to flush the tubing volume.

During the compensation phase, the individual drug proportions areadjusted to provide the desired mixture of drugs in the tubing at thestart of the next scheduled flow rate change, with a total flow rateequal to the Initial flow rate. The result is that the output to thepatient P is exactly as prescribed.

The following equation specifies the length of the compensation orintermediate phase D: ##EQU1##

The time at which the compensation or intermediate phase should startcorresponds to: ##EQU2##

Based on the length of the compensation or intermediate phase D, thesystem 40 can adjust the amount of time during which any given occluderis energized. By keeping the original fluid flow rate but adjusting theproportions of the constituent fluids the tubing member 90 can beflushed by the time that the prescribed fluid flow order requires achange to take place in the fluid flow to the patient.

The multiplexing process is a two step procedure. With respect to FIG.13A, the system 40 carries out a continual volume generating processwhich keeps track of the amount of fluid to be delivered over a periodof time in accordance with the rate previously entered by means ofScreen 2. In an initial step 300, relative rates for each of the fluidsto be delivered are established. In a step 302 accumulators areestablished for each of the fluids. The accumulators keep track of thequantity of fluid that should be delivered in accordance with thepreviously entered delivery schedule. In a step 304 a base timeincrement is determined. In a step 306 the system 40 waits for theduration of the based time increment. In a step 308 the contents of eachof the accumulators is updated. The updated value of each accumulatedcorresponds to the amount of fluid that should have flowed for the basetime increment at the relative rate.

Once each of the accumulators has been updated to reflect the totalvolume of the respective fluid which should have been delivered, thesystem 40 then returns to the step 306 and waits for the next timeincrement. The volume generating process continues updating accumulatorvalues until new relative rates are provided.

With respect to FIG. 13B the process of controlling the occludersassigned to the respective fluids to be delivered utilizes thecontinuously updated values in each of the accumulators. In a step 320 apump constant corresponding to volume per revolution, or volume perlinear movement in the case of a linear pump, is retrieved. In a step322, one of the accumulators is selected. In a step 324 the contents ofthe selected accumulator is divided by the pump constant. This resultsin the number of pump revolutions needed to provide the quantity offluid indicated by the contents of the accumulator. In a step 326 thesystem 40 takes the integer part of the number of pump revolutions. In astep 328 the system checks to see whether or not integer parts have beenformed for all accumulators. If more are needed, the system returns tothe step 322.

If integer parts have been formed for all of the accumulators the system40, in a step 328, selects one of the integer parts. In a step 332 thesystem 40 opens a corresponding occluder. In a step 334 the system 40runs the pump, such as the pump 84 for as many revolutions ascorresponds to the selected integer value. In a step 336 the openoccluder is then closed. In a step 338 the value in the correspondingaccumulator is reduced by the amount of fluid just delivered in the step334. In step 340 the system 40 checks to see whether or not allaccumulators have been reduced. If not, it returns to the step 330 andselects another integer part associated with another accumulator. If so,the system 40 returns to the step 322 to select an accumulator repeatthe process.

In accordance with the above method, a sequence of pulses or quanta ofeach of the predetermined fluids is permitted to flow into the input in90a of the output conduit 90 and is then pumped to the patient P by thepump 84. The above method produces the sequences of fluid quanta such asillustrated and previously discussed in FIG. 11C.

The occluder can preferably be opened and closed during the pump deadband interval. By so limiting the times when occluders can be opened orclosed, only fluid quanta corresponding to integer numbers of pump"revolutions" will be delivered.

It will be understood that while a particular example of a drug orsolution regime was discussed with respect to Screen 2, drugs orsolutions may be specified to the system 40 in a variety of ways withoutdeparting from the spirit and scope of the present invention. Forexample, a drug or solution program could be specified through the barcode reader portion of the light pen 98. Alternately, the desired regimeof drugs and/or solutions could be supplied to the system 40 viatelecommunications through one of the RS232 ports or the modem 156.Finally, the system 40 could contain in its memory a data base of drugnames and doses. The drug names and doses could be displayed on thedisplay unit 96 in response to appropriate input by the operator via thelight pen.

Further, it will be understood that patient information can be input tothe system 40 via the display unit 96. Screen 13 illustrates a patientinformation input screen. By means of such a screen, an operator canenter information such as the patient's name on line 7 as well asphysical information such as sex and age on line 9, height and weight onlines 12 and 14 and allergies on line 16.

The printer 100 can provide a variety of hard copy reports which are inthe nature of historical summaries of patient condition and deliveredfluids over various periods of time. For example, and withoutlimitation, attached hereto in the Addendum as Report 1 is a PhysicianSummary Report which can be generated by the system 40 upon request. Inaddition to patient identification information, the report can includeinformation concerning vital signs, drugs which have been administeredas well as comparisons of drugs to various vital signs.

In addition to those applications discussed above, the system 40 can beused for a variety of different purposes. This includes, patientmonitoring using invasive and noninvasive sensors. Vital signs,temperature, respiration rate, pressures, and urine output could bemonitored. Collected information can be used to turn drug pumps on oroff.

The system 40 could be part of a closed loop feedback system that couldcouple drug dosing algorithms with sensors to create a servo mechanismand maintain prestated physical requirements. Specific examples includevasoactive drugs for blood pressure control and antibioticpharmacokinetic measurements for disease control.

The catheters that currently feed drugs into the patient's venal systemcould be scheduled also to draw blood on command into an automatic bloodtesting system at the bedside for routine tests such as insulin, bloodgasses, or electrolytes.

By incorporating a pH sensor with a fetal heart rate monitor, the system40 could detect fetal stress and automatically alarm and signalreduction in pitocin or other contraction type drugs which are known tocreate acidosis.

In either automatic or manual modes, in addition to IV drugs, the system40 can quickly report other drugs given, other supplies given, otherfoods given, nursing time at the bedside, and all other routine bedsiderecord keeping support tasks necessary for reduced administrative andmedical cost containment.

By using computer curve fitting to predict the rate that a powder,tablet, or high concentration liquid drug will dissolve in standarddiluents, the system 40 could automatically maintain a consistent levelof drug dose to the patient. Current technology tries to find a drugcarrier matrix that dissolves evenly; this would not be necessary withmatching of the dissolution curve with the drugs involved.

In addition, by gathering drug data and coupling it with sensor data,physician trending and relationship graphs will provide insight topatient drug response and will assist in patient management. This datais available both locally in a patient's room and remotely at thephysician's home or office for more responsive drug management.

Since the system 40 has characteristics which tend to reduce patientsepsis and to reduce patient blood contact to one central IV line,patients who have immunosuppressed conditions can more favorably betreated. These patients include patients receiving chemotherapy, thosewith AIDS, bone marrow transplant patients, and others.

The system 40 could also be used to assist in patient pain management.With the addition of a small pushbutton on a cord to the patient,analgesia type drugs can be dispensed in predesignated quantity bypatient demand. When the patient is alert enough, this is a provenmethod to reduce total morphine levels while better serving patientneeds. Current systems are expensive and bulky. They use specialstandalone pumps with high cost narcotic drug containers. The system 40could greatly simplify this technique while significantly reducing cost.

The improved operational characteristics of the system 40 are readilyapparent when compared to a known apparatus 380, FIG. 14A, for thepurpose of introducing a second fluid, fluid B, into a flow of a firstfluid, fluid A. The system 380 includes a solution container 382 whichserves as a source of the fluid A.

Flow of the fluid A from the container 382 is carried by a conventionaltubing member 384 which can include a drip chamber 384A. The tubingmember 384 can be clamped shut by a manually operable clamp 384b. Thetubing member 384 terminates at a Y-junction 386. Outflow from theY-junction 386, via a tubing member 388, passes through a conventionalinfusion pump 390 and is then delivered to the patient at a ratedetermined by the setting of pump 390.

Fluid B, in a container 392 flows therefrom member 394, through a dripchamber 394a and is regulated by a manually operable clamp or occluder394b. Outflow from the tubing member 394 is coupled through theY-junction 386 and can then flow into the tubing member 388.

The two fluid system of FIG. 14A has been commonly used in situationswere fluid A is being delivered to a patient and it is desirable tointerrupt the delivery of fluid A for the purpose of delivering fluid B.Usually the volume of the fluid B in the container 392 is less than thevolume of the fluid A in the container 382.

To provide an additional head to the fluid B, it is supported on ahanger 396 above the container 382. The container 382 is conventionallylowered by means of a short metal hanger 398. When the flow of fluid Bfrom the container 392 is initiated, due to a difference in heights ofthe two containers 382 and 392, the fluid B will drain through thetubing member 388 and in the process will interrupt the flow of thefluid A through the tubing member 388.

FIG. 14B is a pair of graphs illustrating the change in concentration offluids A and B in the tubing member 388 as fluid B drains therethrough.As illustrated in FIG. 14B, initially fluid A corresponds to 100% of thefluid in the tubing member 388. As the fluid B starts to flow, theconcentration of fluid A drops and the concentration of fluid Bincreases toward 100%. Subsequently, when the container 392 has beenemptied the concentration of fluid B in the line 388 begins to decreasetoward zero and the concentration of fluid A in the line 388 returns to100%.

In FIG. 14B the "G" and the "S" identify measured data points. Eachfraction corresponded to 0.4 ml.

In FIG. 14B, percent concentrations, as fluid A is displaced by fluid Band fluid B is displaced by fluid A, are plotted against fractionnumbers of fluid in the line 388. The fluid delivery rate in the line388 is 120 ml/hour. The fluid A could be for example, glucose and thefluid B could be saline.

FIG. 16 illustrates the calculated mixing volume for the system of FIG.14A during the time intervals when fluids A and B are mixed in the line388. During the initial mixing phase, the concentration of Fluid B isincreasing. During the final mixing phase, the concentration of Fluid Ais increasing. Total calculated mixing volume corresponds to 20.2 ml.

Fluid initial mixing volume was calculated starting from when fluid Bfirst appeared and ending when fluid A fell below 5% of its initialconcentration. Fluid final mixing volume was calculated similarly.

In a similar study the system 40, see FIG. 15A, utilized with twocontainers 56a and 56b containing fluids A and B and operated so as todeliver 120 ml per hour provides substantially different results. InFIG. 15B percent concentrations of fluid in the line 90 as the flow offluid A is interrupted and switched to the flow of fluid B usingcomputer controlled occluders 64a and 64b are plotted against thefraction number of fluid in the line 90. As is readily apparent from thegraph of FIG. 15B, the flow concentration of fluid B in the line 90increases substantially faster in the system 40 than does theconcentration of fluid B in the line 388 of the system 380. As a result,the patient starts receiving the fluid B faster when administered by thesystem 40 than in the conventional prior art system.

Further, as illustrated in FIG. 16, the volume of the mixed fluids A andB during the transition intervals when fluid A is decreasing in the line90 and fluid B is increasing as well as the reverse when fluid B isdecreasing and fluid A is increasing has been calculated to be on theorder of 11.9 ml. This latter value is about one-half the earlier notedvalue of mixing volume for the system 380. Hence, the volume of mixedfluids A and B is substantially less with the system 40. As a result,the possibility of interaction between the two fluids has been reduced.In addition, better control has been achieved over the delivery of thefluids to the patient.

FIG. 17 illustrates an alternate occluder head 400 usable with thecomputer controlled occluders 64. The occluder head 400 includes acylindrical solenoid body portion 402 defining an interior region 404which is in part occupied by a solenoid coil 406. An extension 402a iscrimped onto body portion 402.

Centrally located and axially moveable within the housing 402 is asolenoid armature 408. The armature 408 is moveable in a direction 410in response to electrical energy having been applied to the solenoidcoil 406. A compression spring, comparable to the spring 178 can be usedto move the armature 408 opposite the direction 410 when the solenoidcoil 406 is denergized.

The armature 408 carries a cylindrical spacing member 412 whichterminates in a disk-shaped head 414. The head 414, when the solenoidcoil 406 is de-energized will pinch closed the tubing member 74a.

The occluder head 400 also carries a fixedly located clamping member420. The member 420 terminates adjacent the tubing member 74a in acurved extension 422. As the solenoid armature 408 moves opposite thedirection 410, the disk-shaped clamping member 414 forces a region 424of the tubing member 74a against the curved member 422 which clamps thetubing member 74A shut. When the coil 406 is energized, the armature 408and the disk-shaped member 414 move in the direction 410 away from theregion 424 thus permitting a flow of fluid through the tubing member74A.

An annular seal 430 located between a groove 402b in the housingextension 402a groove 414a in the disk-shaped member 414 seals theoccluder head from incident spilled fluids as well as from cleaningfluids which might be used for the purpose of cleaning the exteriorsurfaces of the system 40. The annular seal of 430 could be formed ofany flexible material which will be resistant to fluids and cleaningsolutions of a type normally found in a healthcare environment.

It should be noted that while the previous discussions refer to theentry of information through the display 96 by means of the light penportion of the bar code reader light pen member 98 it will be understoodthat such information can also be entered directly off of labels ordocuments by means of the bar code reading portion of that member inrandom order. For example, it would be possible to encode admissionforms or other documents with a bar code which carries an indicium ineach field in bar code format which specifies where on the correspondingscreen the related information is to be entered. Additionally, by meansof selected bar code characters it would be possible to envoke variousfunctions through the bar code reader analogously to the way in whichthose functions are envoked by means of the light pen.

Hence, by means of the bar code reading portion of the member 98preprinted data in a bar code format can be conveniently and quicklyentered into the system 40. In addition, labels on the solutioncontainers 56 can also be printed with bar code format encodedinformation identifying the related solutions, drugs, delivery rates andvolumes. Such information can all be entered into the system 40 by meansof the bar code reading portion of the member 98.

It will also be understood that a variety of other sensors can becoupled to the system 40 for the purpose of sensing and recording otherpatient related data. These sensors could include but are not limited toblood pressure sensors, temperature sensors or the like.

It will also be understood that the system 40 can be operated in avariety of ways. In one mode of operation, a flush fluid, such assaline, can be used to separate two otherwise incompatible fluids.Imposing a requirement that there be a quantum of flush fluid betweenspaced apart quanta of incompatible fluids can be carried out throughthe display monitor 96.

As an alternate to the use of a liquid as a flush fluid, a gas, such asair, or oxygen could be used as a flush. In such an instance, thegaseous flush quantum which is located between two spaced apart quantaof incompatible fluids is withdrawn from the patient delivery tubingmember 90 immediately prior to coupling to the catheter C at the end90c. Further, it will also be understood that when a gas is used as aflush fluid to space apart incompatible quanta of liquids, it is alsopossible to precisely measure the length of each liquid quantum andaccumulate the number of quanta which are delivered to the patient toprovide very precise volume and rate information.

As yet another alternate, air pressure can be used as an alternate tothe pump 84 to drive the delivery of fluid in the line 90 to thepatient. In this embodiment, the driving gas is injected into the tubingmember 90, perhaps also functioning as a flush fluid, and forcing thefluid therein to the patient.

As yet another alternate, it will be understood that the system 40 couldbe used in a gravity flow mode without a pump. This results in a lowpressure injection of fluid into the patient.

It will be understood that by means of optics and the use of spacedapart quanta of gases injected into the tubing member 90 that it ispossible to accurately determine the internal tubing diameter to controlthe volume of delivered fluid more precisely. This is particularlyadvantageous wherein the tubing member 90, which can have a nominaldiameter on the order of 0.065 inches is a disposable which is regularlyreplaced. The replacement tubing may have an actual diameter whichvaries somewhat from the nominal value of the diameter. By use of thisself-calibrating feature such diameter variations can be compensatedfor.

It will also be understood that in yet another embodiment, it ispossible to differentiate between a quantum of liquid and a quantum of agas such as air. This detection process utilizes the property that thetransmissive or reflected characteristics of a liquid are different fromthose of a gas. Hence, it is possible to differentiate and determine thepresence or absence of a liquid or a gas. As a correlation, such adevice can also be used as an air detector for the purpose ofeliminating undesirable air in the line 90.

From the foregoing, it will be observed that numerous variations andmodifications may be effected without departing from the true spirit andscope of the novel concept of the invention. It is to be understood thatno limitation with respect to the specific apparatus illustrated hereinis intended or should be inferred. It is, of course, intended to coverby the appended claims all such modifications as fall within the scopeof the claims. ##SPC1##

We claim:
 1. A multi-fluid delivery system for delivering a plurality ofpreselected fluids from a plurality of fluid flow sources to a fluidflow delivery port comprising:a plurality of deformable flow means forreceiving fluid flow from the plurality of fluid flow sources; aplurality of flow control means with each of said deformable flow meansclosable by a corresponding one of said flow control means; means forcombining fluid flow from selected of said flow means to form a combinedfluid flow output combination at said delivery port; and programmablecontrol means, coupled to each of said flow control means for storing,at least, one required fluid flow delivery schedule and for actuatingone or more of said flow control means such that said selected fluidsflow into said combining means in accordance with said stored, fluidflow delivery schedule with said programmable control means includingmeans for storing information relating to inter-fluid compatibility andfor displaying an indicium of compatibility between at least two of saidspecified fluid types prior to activating any of said flow controlmeans.
 2. A system as in claim 1 wherein said programmable control meansincludes means for scheduling intermittent actuation of one or more ofsaid flow control means so as to permit measured quantities ofrespective fluids to flow into said combining means in accordance withsaid fluid flow delivery schedule.
 3. A system as in claim 2 with saidprogrammable control means including means for simultaneously actuating,at least, two of said flow control means for selected time intervals. 4.A system as in claim 3 with said programmable control means includingmeans for sequentially actuating, at least, two of said flow controlmeans for selected time intervals.
 5. A system as in claim 2 with saidprogrammable control means including means for sequentially actuating,at least, two of said flow control means for selected time intervals. 6.A system as in claim 5 with said scheduling means including compensationmeans for adjusting actuation of selected of said flow control means topermit flow of selected fluids so as to minimize fluid flow transientsin said combining means in response to said programmable control meanschanging said combined fluid flow.
 7. A system as in claim 5 with saidscheduling means including means for predicting when said scheduledactuation should be altered so as to continue to deliver said combinedfluid flow at said delivery port pursuant to said delivery scheduleuntil a succeeding combined fluid flow is to be delivered.
 8. A systemas in claim 5 with said sequentially actuating means including means fordetermining at least first and second time intervals for repetitivelyactuating corresponding ones of said fluid control means.
 9. A system asin claim 2 including means for visually displaying a manually operablekeyboard usable for specifying one or more fluid flow deliveryschedules.
 10. A system as in claim 2 including means for pumping saidcombined fluid flow to the delivery port at a controllable rate andincluding means to actuate said pumping means in accordance with apredetermined delivery schedule.
 11. A system as in claim 2 includingfluidic means for providing said combined flow rate at said output portin accordance with said delivery schedule.
 12. A system as in claim 2including means for sensing a pre-printed bar code usable for specifyingone or more delivery schedules.
 13. A system as in claim 2 includingmeans for coupling at least one sensor to said control means.
 14. Asystem as in claim 2 including means for generating a selected hard copyand for spooling selected information thereto.
 15. A system as in claim14 including means for transferring at least part of said spooledinformation to said hard copy in response to detection of apredetermined condition.
 16. A system as in claim 14 including operatorresponsive means for selecting and formatting information to betransferred to said hard copy.
 17. A multi-fluid delivery system fordelivering a plurality of preselected fluids to a fluid flow deliveryport comprising:a plurality of deformable flow means for receiving fluidflow from a plurality of fluid flow sources; a plurality of flow controlmeans with each of said deformable flow means closable by acorresponding one of said flow control means; means for combining fluidflow from selected of said flow means to form a combined fluid flow; andprogrammable control means, coupled to each of said flow control meansfor storing a plurality of selected fluid flow delivery schedulesincluding fluid type and a selected delivery parameter for each type andfor actuating one or more of said flow control means such that selectedfluids flow into said combining means in accordance with one of saidstored delivery schedules and including compensation means for adjustingactuation of selected of said flow control means to sequentially blendselected of the fluids so as to minimize fluid flow transients at saiddelivery port in response to said programmable control means switchingfrom a first to a second fluid flow delivery schedule.
 18. A system asin claim 17 wherein said programmable control means includes means forscheduling intermittent actuation of one or more of said flow controlmeans so as to permit measured quantities of respective fluids to flowinto said combining means in accordance with a predetermined deliveryschedule.
 19. A system as in claim 18 with said programmable controlmeans including means for sequentially actuating, at last, two of saidflow control means for selected time intervals.
 20. A system as in claim18 with said programmable control means including means for determiningwhen said control means should be actuated prior to switching a first toa second fluid flow delivery schedule so as to minimize fluid flowtransients.
 21. A system as in claim 18 including means for pumping saidcombined fluid flow to said delivery port at a preselected rate.
 22. Asystem as in claim 21 wherein at least some of said selected deliveryparameters correspond to a desired flow rate of a respective fluid. 23.A system as in claim 22 and including means to actuate said pumpingmeans to provide a required combination flow rate at the output port inresponse to said specified flow rates.
 24. A system as in claim 21including visual display means for display and entry of selectedinformation.
 25. A system as in claim 20 including means for storinginformation relating to inter-fluid compatability and for testingcompatibility between said specified fluid types prior to activating anyof said flow control means.
 26. A system as in claim 17 with said flowcontrol means including solenoid actuating means.
 27. A system as inclaim 26 with each of said solenoid actuating means including asolenoid.
 28. A system as in claim 26 including variable power drivemeans coupled to each said solenoid actuating means.
 29. A system as inclaim 17 wherein said combining means includes a sealed housing definingan elongated fluid combining region and a plurality of sealed fluidinput ports coupled thereto.
 30. A system as in claim 29 with each ofsaid input ports including pierceable closing means.
 31. A system as inclaim 30 with each said input port covered by a removable sealing cover.32. A system as in claim 30 with each said closing means including apierceable but resealable member with a thickness on the order of 0.25inches.
 33. A system as in claim 32 with each said resealable memberhaving a generally cylindrical peripheral surface.
 34. A system as inclaim 29 wherein said elongated fluid combining region has a circularcross section.
 35. A system as in claim 29 with said housing including afluid output port.
 36. A system as in claim 29 with said housingincluding means for coupling another housing thereto.
 37. A closedsystem for controllably delivering predetermined quantities of at leastfirst and second fluids from first and second sources comprising:firstand second fluid flow means each couplable to a respective source; firstand second blocking means each positionable adjacent a respective flowmeans for permitting the flow of fluid therethrough in response to anapplied electrical signal; sealed fluid flow junction means coupled tosaid first and said second flow means for combining first and secondfluid flow to a single output at an output flow port; an output fluidflow conduit coupled to said output port of said fluid flow junctionmeans; means for specifying a first fluid flow delivery scheduleincluding at least rate information for each of the fluids; means fortranslating said specified delivery rates into first and secondsequences of electrical signals applied to said first and secondblocking means so as to form first and second sequences of spaced-apartfluid quanta, corresponding to said first and second fluids, withmembers of each said sequence flowing into said junction and thenflowing into said output conduit and with members of said first sequenceinterspersed between members of said second sequence, said membersmixing in said conduit so as to provide an output fluid flow includingthe first fluid at said first specified flow rate and the second fluidat said second specified flow rate.
 38. A closed system as in claim 37including means for specifying total fluid volumes to be delivered. 39.A closed system as in claim 38 including means for storing a pluralityof specified flow rates and volumes for use as a historical record. 40.A closed system as in claim 39 including means for generating hard copydisplaying said stored plurality of specified flow rates and volumes.41. A closed system as in claim 38 including means for testing forcompatability between said first and said second fluids.
 42. A closedsystem as in claim 37 including means for specifying a second fluid flowdelivery schedule and means for adjusting said sequences of electricalsignals so as to minimize fluid flow transients at said conduit outputport when the system switches from said first to said second fluid flowdelivery schedule.
 43. A system as in claim 42 wherein said switchoccurs at a predetermined time and including means for automaticallyestablishing a third-intermediate fluid flow delivery schedule, prior tosaid predetermined time, and including means for switching from saidfirst to said third schedule prior to said predetermined time and fromsaid third to said second schedule at said predetermined time so as tominimize fluid flow transients at said output port.
 44. A closed systemas in claim 37 wherein said output conduit can be coupled to a fluidreceiving patient and including feedback means, coupled between thepatient and said translating means, for regulating delivery of at leastone of the fluids in response to sensed feedback indicia.
 45. A closedsystem as in claim 37 with said specifying means including visualdisplay means through which fluid flow parameters can be entered.
 46. Aclosed system as in claim 45 with said display means including means forrevising previously entered fluid flow parameters.
 47. A closed systemas in claim 37 including means for coupling a plurality of sensorsthereto so as to receive selected information therefrom.
 48. A closedsystem as in claim 37 with said blocking means each including anelectrically activatable solenoid.
 49. A closed system as in claim 37with said fluid junction means formed with a plurality of sealed,pierceable, fluid access members in fluid flow communication with anelongated fluid flow path, said path in fluid flow communication withsaid output conduit.
 50. A closed system as in claim 49 with each saidpierceable fluid access member including a pierceable rubber seal.
 51. Aclosed system as in claim 50 with said fluid junction means including alaterally extending, elongated operator protecting shield member.
 52. Aclosed system as in claim 37 with said specifying means including meansfor entry of delivery rates or volumes of a plurality of fluids to bedelivered.
 53. A closed system as in claim 52 with said means for entryincluding display means through which said rate or volume informationcan be entered.
 54. A closed system as in claim 37 with said junctionmeans including means for slidably engaging said specifying means.
 55. Asystem for delivery of a plurality of fluids to a patient and forproviding hard copy records relating thereto comprising:at least firstand second fluid flow means each couplable to a respective fluid source;at least first and second blocking means each positionable adjacent arespective flow means for permitting the flow of fluid therethrough inresponse to an applied electrical signal; fluid junction means coupledto at least said first and said second flow means; an output fluid flowconduit coupled to said fluid flow junction means and with a free outputend; means for specifying a fluid flow delivery schedule at said outputend; means for translating said specified delivery schedule into firstand second sequences of electrical signals applied to said first andsecond blocking means so as to form first and second sequences ofspaced-apart fluid quanta corresponding to said first and second fluidswith members of each said sequence flowing into said junction and thenflowing into said output conduit with members of said first sequenceinterspersed between members of said second sequence and with saidmembers mixing in essentially only said conduit so as to provide anoutput fluid flow at said output end including the first fluid and thesecond fluid in accordance with said specified delivery schedule; andmeans for generating a record related to said delivery schedule.
 56. Asystem as in claim 55 including means for sensing a predeterminedindicium carried on a planar member.
 57. A system as in claim 56 whereinsaid sensing means includes a bar code reader and said indicium is apre-printed bar code on said planar member.
 58. A system as in claim 57wherein said planar member is a label affixed to a fluid source.
 59. Asystem as in claim 58 means for determining and storing fluid type inresponse to having sensed a respective indicium.